I haven't had to set a resizing die since 2005 and wanted to get some advice as I'm a little rusty.

All my rifles are bolt action and used for hunting purposes. All my dies are RCBS full length.

When I first got my .270 wsm I bought 2 boxes of Winchester factory ammunition. This ammunition was loaded very hot and really expanded out the cases. So what I was able to do to set this die, was to back it off a turn and slowly increase the turn until the case would no longer fit in the rifle. Then kept increasing the (turning in/down) die until the case just fit nicely. Just at the point where the bolt closed nicely.

However on my .300 wsm I was never able to achieve this as I never bought factory ammunition. I purchased new cases and never loaded them hot enough to expand like the factory ammo. So I remember doing a lot of fiddling around with this die and don't know that I ever got it set right. No longer have this gun. Did just buy another though but won't be shooting this rifle til spring.

Now I'm getting ready to set the resizing die for my new .308 Win and Lapua brass. I have Stoney Point (now Hornady) head and shoulders measuring tools so I have measured my cases. I have loaded a lot of different powder measurements while working up loads so I have many different measurements so the cases measure all different sizes.

So do I

A. Use the method I used with my .270 wsm where I back the die off and then keep turning in until the case doesn't fit and then turn a little more until it fits. My concern here is that the cases are not expanded enough and this method will not work. But have never worked a .308 Win before.

B. Take the longest head and shoulders measurement and set the die until I slightly push back the shoulder on the longest cases. This will leave the brass in slightly different sizes. Then after firing all my brass again repeat this step slowly getting them to finally fit perfect for my rifle.

C. Take the shortest head and shoulders measurement and set the die to this measurement so that when I'm done all my brass will be the exact same size. Then after firing all my brass again repeat this step slowly getting them to finally fit perfect for my rifle.

D. None of the above as I'm an idiot and have no clue what the he77 I'm doing.



Thanks,
Adams

I think you do know what to do.
Make the brass fit your chamber as close as possible; don't over size it. First try your brass in your chamber so you know how it fits before you do anything to it. Ideally you would fire form it but no one does that with standard calibers. So just fire it and then set your die so the shoulder is not pushed back any more than allows good chambering.

Do I use method A to do this? Or all done by measuring shoulders?

The Hornady cartridge case headspace gauge will tell you the fired cases headspace length. Just remember the case springs back and is a smidgen smaller than the chamber.

Now set your full length die to size the case .001 to .002 shorter than its fired measurement length.

This is more than good enough and tells you more than "feel" when closing the bolt on a sized case.

After decades of cranking dies in and out, I finally broke down (on the advice of a good friend) and bought a few sets of Redding competition shell-holders. You only need the one set for both calibers.

At first use the + .010" holder, screwed in hard against the die plus 1/4-12 turn. After a firing or three they will likely start to chamber with a bit of effort. When that happens, take the expander stem out and go to the .008 holder and trial fit it. Keep going down .002" at a time with the same case until you get just a hint of pressure when lowering the bolt handle. That's your magic number for that die, those brass and that chamber so write it on the die box and ammo box. Put the stem back in and push the case neck over expander ball.

ARRG!!! All these gauges do but one thing; make money for the gauge makers. They know nothing about your chamber, nor your brass size or condition, nor it's ductility, so you are falling into a trap that is as wide as the SAAMI tolerances, which, in some cases are positively huge. (In terms of up to .018 between a min brass and a max chamber) No gauge in the world can do anything but put you into an average. Assuming the rifle and ammo makers even follow them in the first place. So, if you really want to fit brass to your chamber, then do so, but using a gauge does not do that except by accident. I usually don't reload using the accidental fit method; OK, sometimes I do.

quote:

Originally posted by dpcd:
ARRG!!! All these gauges do but one thing; make money for the gauge makers. They know nothing about your chamber, nor your brass size or condition, nor it's ductility, so you are falling into a trap that is as wide as the SAAMI tolerances, which, in some cases are positively huge. (In terms of up to .018 between a min brass and a max chamber) No gauge in the world can do anything but put you into an average. Assuming the rifle and ammo makers even follow them in the first place. So, if you really want to fit brass to your chamber, then do so, but using a gauge does not do that except by accident. I usually don't reload using the accidental fit method; OK, sometimes I do.

+1
I've said you can't buy your way into the winner's circle. Nor can you "thingy" your way into sub MOA ammo. Sooner or later, you've got to shoot the stuff. And then you find out if YOU are a sub MOA shooter.

you can measure everything in the room, but if the cases don't chamber none of it matters.

you want just enough of the case sized for the round to freely chamber.
many times this means just pushing the neck down to hold the bullet in place.

As mentioned above I have used 1-fired cases in 270 and 300 WSM cartridges that must have been loaded to very high pressures. I would set my size die so it touched the shellholder on full stroke of the press handle. That was the only way I could chamber those 1-f cases. Once fired in my rifle I did not want to push the shoulder back each time I resized the case . Instead of constantly adjusting size dies or buying a bunch of expensive measuring devices I went down to the hardware store and bought a bag of 3/4 to 1/2 inch conduit reducing washers. Flatened out the reducing washer and insert the washer under the size die. The die is set to FL size and with the washer inserted under the die the shoulder is not pushed back .The case chambers nicely in all bolt actions previously fired in and cases last forever. I have a reducing washer in each set of dies I have (around 100 different calibres). These washers can also be used to adjust bullet seating depth without adjusting the seating die. These washers sell for approx. 10 cents ea.

quote:

Originally posted by dpcd:
ARRG!!! All these gauges do but one thing; make money for the gauge makers. They know nothing about your chamber, nor your brass size or condition, nor it's ductility, so you are falling into a trap that is as wide as the SAAMI tolerances, which, in some cases are positively huge. (In terms of up to .018 between a min brass and a max chamber) No gauge in the world can do anything but put you into an average. Assuming the rifle and ammo makers even follow them in the first place. So, if you really want to fit brass to your chamber, then do so, but using a gauge does not do that except by accident. I usually don't reload using the accidental fit method; OK, sometimes I do.

Actually the gauges give me accurate measurments, there is a big difference between "feel" and using a black felt tip marker.

Below measuring a "fired" .223/5.56 case and then setting the die up for the proper shoulder bump.



Below the same gauge can be calibrated to read actual headspace gauge length.





Its the ability of the human to use tools that seperates him from the apes. (and shade tree hammer and chisel mechanics) ARRG!!!

I have friends who pride themselves on how well they can load ammo, to fit gauges. I ask them, "How does your gauge know how long your chamber is in relation to that gauge?" The answer is always that they have no idea. There are a lot of assumptions and tolerances built into rifles, brass, and dies. So they are making brass to fit a gauge that has some unknown relationship to the chamber. Look at the SAAMI specs and you will see. Gauges and mics give you precise measurements; not necessarily accurate ones. Accuracy being defined as how well the brass fits the chamber.
Now, if your gauge and chamber were cut with the same tooling, then that would be different, but usually they are not. They were made hundreds of miles apart to fit somewhere within some suggested specification that no one is bound to follow and is several thousandths wide at best.
Precision is not accuracy no matter how finely you slice it.
I see that the previous cartoon poster, that he uses fired brass to set his gauge; that is no different than setting the sizing die to make the brass fit the chamber. Just takes more equipment about which a newbie reloader does not need to be concerned nor confused.

My gauges tell me how long my chambers is and how long my fired and sized cases are.

With brass spring back and work hardening the shoulder locations after firing and sizing can vary .003 or more.

If you use a sized case to check bolt closing effort did you use a long case or a short case.

I use Redding competition shell holders to set my shoulder bump. And never have to touch the die to do this. On top of this these shell holder all allow hard contact with the shell holder and press cam over

This means more uniform shoulder bump and case that vary less in headspace length.

I'm 67 and have been reloading for over 47 years and don't guess about chamber and case length.

There are crude simple methods and very accurate methods. And I do not live in the dark ages and my knuckles don't drag on the ground.

And Gauges do tell any reloader a great deal, and we don't have to guess.